<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.7.10/dist/vue.min.js"></script>
</head>

<body>
    <div id="box">
        <img :src="img">
        <button v-on:click="btn">点我切换图片</button>


    </div>
    <script>
        var vm = new Vue({

            el: '#box',
            data: {
                img: 'img/1.jpg'

            },
            methods: {
                btn() {
                    if (this.img == 'img/1.jpg') {
                        this.img = 'img/2.jpg'
                    } else {
                        this.img = 'img/1.jpg'
                    }

                }
            }

        })
    </script>
</body>

</html>